YBX1 and glioblastoma: For instance, it has been shown that overexpression of GOLPH3 in the human glioblastoma cell lines U87 and U251 contributes to their malignant motility by enhancing different aspects that are associated to this tumorigenic property, such as the activity of the mTOR-signaling pathway, the levels of the small GTPase RhoA, the levels of the gene expression regulator YB1, and the degradation of extracellular matrix by matrix metalloproteinase-2 (MMP-2) [12, 42].